Many rare and/or endemic species exhibit one or more of the following attributes which make them especially prone to extinction: (1) narrow (and single) geographical range, (2) only one or a few populations, (3) small population size and little genetic variability, (4) over-exploitation by people
Answer:
a. HCl.
b. 0.057 g.
c. 1.69 g.
d. 77 %.
Explanation:
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In this case, since the reaction between magnesium and hydrochloric acid is:

Whereas there is 1:2 mole ratio between them.
a) Here, we can identify the limiting reactant as that yielded the fewest moles of hydrogen gas product via the 1:1 and 2:1 mole ratios:

Thus, since hydrochloric yields fewer moles of hydrogen than magnesium, we realize it is the limiting reactant.
b) Here, we use the molar mass of gaseous hydrogen (2.02 g/mol) to compute the mass:

c) Here, we compute the mass of magnesium associated with the yielded 0.0248 moles of hydrogen:

Thus, the mass of excess magnesium turns out:

d) Finally, we compute the percent yield, considering 0.044 g is the actual yield and 0.057 g the theoretical yield:

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Answer:
D. chlorine, oxygen, nitrogen, hydrogen.
Explanation:
- Thomas Graham found that, at a constant temperature and pressure the rates of effusion of various gases are inversely proportional to the square root of their masses.
<em>ν ∝ 1/√M</em>
where ν is the rate of effusion and M is the atomic or molecular mass of the gas particles.
- The molecular mass for the listed gases are:
O₂: 32.0 g/mol,
Cl₂: 70.906 g/mol,
N₂: 28.0 g/mol,
H₂: 2.0 g/mol.
- Hence, the smallest molecular mass of the gas, the fastest rate of effusion.
So, the order from the slowest to the fastest rate of effusion is:
<em>Chlorine, oxygen, nitrogen, hydrogen.</em>
Answer:
d i dont now but im sure my answer is d im not good to write english word